Effects of pulse level of Nd-YAG laser on tensile properties and formability of laser weldments in automotive aluminum alloys
Effects of pulse level of Nd-YAG laser on tensile properties and formability of laser weldments in automotive aluminum alloys
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DOI：
10.1016/j.msea.2005.10.041
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发表时间：
2006-01-25
期刊：
影响因子：
6.4
通讯作者：
Lin, HC
中科院分区：
文献类型：
--
作者：
Kuo, TY;Lin, HC
拉伸性能和成型性是许多应用中的重要参数。作为一种轻质材料，铝越来越多地用于汽车车身板的制造。本研究对两种常用的汽车车身面板铝合金 5754-O 和 6022-T4E29 进行无填充金属的对焊。使用矩形波形式的 Nd-YAG 激光器进行焊接，该激光器具有不同的脉冲电平 (Delta P)，但平均功率恒定为 1.5 kW。对于这两种合金，结果表明，成功对接所需的行进速度随着 Delta P 的减小而增加。对于恒定的脉冲水平，镁含量较高的 5754-O 合金（2.9 wt.% Mg）所需的行进速度大约是镁含量较低的 6022-T4E29 合金（0.61 wt.% Mg）所需的行进速度的 2.5 倍。此外，结果表明，两种合金焊件的抗拉强度、延伸率和成形性均随着 Delta P 水平的降低而增加。在 5754-O 合金中，这些趋势主要归因于焊接过程中镁蒸发、微观结构细化以及所得焊缝孔隙率的降低。然而，对于6022-T4E29，Mg的蒸发并不显着，因此，孔隙率的变化并不大。这些结果是由于母材中镁含量较低造成的。因此，焊件机械性能的提高是焊缝微观结构细化的结果。 (c) 2005 Elsevier B.V. 保留所有权利。
Tensile properties and formability are important parameters in many applications. Being a lightweight material, aluminum is increasingly employed in the fabrication of automotive body panels. This study performs butt welding without filler metal on two frequently used automotive body panel aluminum alloys, 5754-O and 6022-T4E29. Welding is conducted using a Nd-YAG laser with a rectangular wave form having various pulse levels (Delta P) but a constant mean power of 1.5 kW. For both alloys, the results indicate that the travel speed required to achieve a successful butt joint increases as Delta P decreases. For a constant pulse level, the travel speed required for the higher Mg content 5754-O alloy (2.9 wt.% Mg) is approximately 2.5 times that of the lower Mg content 6022-T4E29 alloy (0.61 wt.% Mg). Additionally, it is shown that the tensile strength, percentage elongation and formability of both alloy weldments increase with decreasing Delta P level. In the 5754-O alloy, these trends are attributed primarily to the occurrence of magnesium evaporation during the welding process, microstructure refining, and porosity reduction in the resultant welds. However, for 6022-T4E29, the evaporation of Mg is not significant, and consequently, the variation in porosity is not great. These results are caused by a lower Mg content in the base metal. Therefore, the enhancement of the mechanical properties observed in the weldments is a result of a refinement of the weld microstructure. (c) 2005 Elsevier B.V. All rights reserved.